This article is from the Mac communications FAQ, by Bruce L Grubb BruceG6069@aol.com with numerous contributions by others.
A commmunication connection was the original way home computers
remotely connected to other computers. It basicly consisted of
a direct connection between the personal computer to the computer
on the other end of the phone line.
Originally each communication program had its own method and
interface but then Apple created the Communications Toolbox (CTB)
as a standard interface for programmers writing communications
programs. In addition, specific "tools" that interfaced with
modems, provided terminal emulation, or handled file transferring
could be implemented as external add-on features to CTB-aware
The protocals most commonally associated with commmunications
software are (in order of preferance): Zmodem, YModem, Xmodem,
and finally Kermit. However because it was a direct connection
you could only do one thing at a time and the interface tended to
be at best a Command Line Interface.
By contrast Internet connections grew out of the development of
personal computers. Originally Internet computers were directly
connected to each other providing information to the user via dumb
termanals. With the development of personal computers a need to
allow dial in connections developed with SLIP and PPP (see [5.3])
being the result. These additional protocals allowed personal
computer users to use such Internet protocals as FTP, Gopher, and
Most importantly via PPP Internet connections allowed multiple
connections through one modem allowing the user to perform several
tasks at once. Due to this multifunction ability continued development
of communication programs has fallen off in favor of the more robust
Internet programs though they are still the best way to connect to
a local BBS.
Since support for Internet connections was rolled into the MacOS
beginning with System 7.5 it has become the defacto way to link a
personal Mac to the outside world.